Sound or vibration transmitting apparatus



Apnik L IQSQ, E. wENsLl-:Y

SOUND OR'VIBRATION TRANSMITTING APPARATUS Filed May l0, 1928 //7 Ven for far/ Wens/ Patented Apr.. 1, 193.0

UNITED STATES EARL wENsLnY, or creano,

PATENT; OFFICE ILLINOIS,ASSIGNOR T0 WESTERN ELECTRIC COMPANY,

INCORPORATED, OF NEW YORK, N.v Y., A CORPORATION OF NEW YORK souiin on vrBnATIoN rnANsMrrrme ArPAaA'r'Us Application led MayvIO, 1928. Serial No. 276,656.

A This invention relates to' sound or vibration transmitting apparatus, and, more particularly to a device for damping the vibrations in sound transmitting apparatus.

4g5 Damping devices are known in the prior art which operate upon the principle of expelling air from the interstices between leaves of paer and again drawingair between the leaves y creating a vacuum upon separating the 1o leaves. Certain difficulties have been experienced, however, 'in providing a device of thistype in which the numerous leaves act uniformly so that their total eifect maybe determined from their number and in which the damping effect is uniform over the area of the damping device.

It is an object of this invention to provide a damping device having a high degree of veiiiciency and dependability and which may 2o be easily manufactured and assembled.

' 1n accordance with the general features'of the invention, an acoustic apparatus such as a telephone transmitter is provided with av damping device consisting of a plurality of integrally interconnected annular leaves supei-imposed upon one another to form a ring which is agitated by connecting a vibrating member of the acoustic apparatus to an end leaf, thereby producing a damping effect upon the vibrating member due to the compression and rarefaction of the air between Aadjacent leaves. It is believed that a complete understanding of the apparatus may be had by reference to the following description taken in conjunction with the accompanying drawing, in which v Fig. 1 is a fragmentary cross-sectional view of a telephonehand set having a sound or vibration transmitting device employing a damping rdevice embodying the features'of the invention; v

Fig. 2 is an elevational detail view showing a diaphragm withdrawn from a stationary container to extend the damping device;

3 is an elevational view of the damping evice'of Fig. 2 rotated through an angle of 90 degrees, and

Fig. 4 i8 an end view of the damping de- .50 vice.

i The invention is illustrated in connection I with a sound transmitting apparatus or telehone transmitter'having acup-shaped memlier 7 which supports a resistance varying unit. Firinly secured within the cup-shaped member 7 is a rigid ymember 8'which is provided with' a circular central opening over which a cap 9 is fitted which serves as an electrode and forms a cavity for retaining resistance varying material of any suitable type, such as comminuted carbon particles. The lower end of the cavity is enclosed by a cone-shaped diaphragm 10 having a plane circular surface facing the cavity. Dia- Vphragms, such as used 1n acoustic apparatus,

have a more or less marked natural period of vibration for one or more frequencies and when acted upon by impulses at or near these frequencies or their harmonics they will respond much more than'at other frequencies. Because of this natural frequency and the resultant inequalities of ,response between impulses of diiferent'frequencies, the diaphragm may disturb and distort speech waves when their frequency falls within the range of the natural eri'od of the diaphragm.

'ln or er to reduce this maximum response at resonance to negligible proportions, a damping device 1 1 of paper or other suitable flexible material is interposed between the rigid member 8 and the diaphragm 10. This damping device also serves to close the gap between the diaphragm and the rigid member 8 to retain'the carbon partitcles within the cavity of the ca 9. The damping device consists of a num er of annular leaves alter- :nately interconnected at opposite sides along a chord of the annulus. One of Athe end leaves is attached to the rigid member 8 -by a suitable adhesive composition and the other end ring is Isimilarly attached to the diaphragm. When, during the vibration of the diaphragm, the diaphragm moves toward the damping device there will be a compression of the air between the leaves accompanied by an expulsion'of some of the air, and when the diaphragm moves away from the damping devlce the leaves will tend to separate, producing a rarefaction ofthe air between the leaves accompanied by a. movement of the air mg a central opening and alternately intervsponsive to all frequencies.

thirty degrees of the tothe damping device,.which results ina restraining action upon the movement of the diaphragm tending to render it uniformly re- The dampingdevice 11 may be made in two parts each consisting of six leaves 12 without affecting the operatlng characteristics of the device. When the damping device is made in two parts, the end leaves of the assembly should be attached to the diaphragmand the rigid member by adhesive material as shown in Fig. 2. It has been found that when the damping device is made in one integral part it is not essential to attach the end leaves to the diaphragm and the rigid member, although-this may be done.

It is an important feature of this invention that the air has free and uninterrupted access to the interstices between the leaves for a vlarge part of the circumference of the annular leaves.- This is due to that fact that the points at which the leaves are hinged alternate and the chord along which the hinge isl formed, substends only an arc of substantially periphery of a leaf. By constructing the leaves of the damping device of substantially uniformannular width around the entire periphery of the damping device, a uniform damping effect at all points of contact with the diaphragm is insured. 'In Fig. 2, the rigid member, 8 and the diaphragm 10 are shown disassembled with the end leaves of the damping device attached to these members and with the leaves of the damping device extendeds'howing them alternatel)r interconnected at opposite sides. Such adamping device is easily handled without danger of disarranging the leaves and may be readily assembled with the leaves in superposed position.

It'will, be understood that the embodiment v of the ,invention herein described and illustrated is' merely a convenient and useful form of the invention which other modifications with the spirit and scope of the invention. 1

hat is claimed is:

1. In a transmitter, a diaphragm, and a damping devicel associated with the diaphragm comprising a plurality of annular sides.

2. In a transmitter, a dia damping device associated with the diaphragm comprising a plurality of leaves havconnected on opposite sides by a hinged joint opening. A

3. I n a transmitter, a diaphragm,and a damping device associated with the diaphragm comprising a of less length than a dimension of the central ternatel interconnected at opposite sides'by a short inged joint.

. nected at op is capable of manyr ut departing from eaves alternately interconnected on opposite l In a transmitter, a vibratory element,V

bratory element 4comprising a plurality of superimposed leaves alternately interconosite sides, more 4than one-half of the perip ery of each leaf being free to move independently of other leaves.

5. In a vibratory apparatus, a vibratory element, and a damping' device associated' with the vibratory element comprising a plurality of circular leaves having a central aperture, said leaves being alternately hinged on opposite sides along cular periphery.

6. In a transmitter, a diaphragm, and a damplng deviceassociated therewith com-v prising a plurality of annular leaves-having alternately interconnected portions on opposite sides, said interconnected portions being parallel to each other and normal to a diameter of the annular leaves. 7. In a transmitter, a diaphragm, a rigid member, and a damping device. therebetween consisting of a plurality of integrally interconnected annular leaves.

8. In a transmitter, a diaphragm, member, a conical member containing comminuted 'plurality of superimposed interconnected annular leaves between the rigid vmember and the conical member for damping vibrative responses `ofthe diaphragm and for preventing leakage of the comminuted matter from the conical member.

In witness whereof, I hereuntoV subscribe my name this 27th day of April A. D. 1928.

EARL WENSLEY.

phragm, and a- I plurality of leaves ala rigid resistance-varying material, and a achord of their cir- 

